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H. 0. RIGHTMIRE. HOLDDOWNFOR KNITTING MACHINES.-

No. 513,441. Patented Jan. 23, 1894.

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H. G. RIGHTMIRE.

HOLDDOWN FOR KNITTING MAGHINES.-

No. 518,441. Patented J 23' 894;

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"QRMWWIIIIIMII mm 11v VEN TOR 'ITED STATES PATENT OFFICE.

HARRY C. RIGHTMIRE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO THOMAS A. PEARCE, OF SAME PLACE.

HOLDDOWN FOR KNITTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 513,441, dated January 23, 1894,

Application filed June 22,1889.

To all whom it may concern:

Be it known that I, HARRY O. RIGHTMIRE, of Philadelphia, in theState of Pennsylvania, have invented a new and useful Hold-Down for Knitting-Machines, whereof the following is a specification, reference being had to the accompanying drawings.

In said drawings, Figure 1 represents a view, in perspective,of one form of my invention, the needle cylinder and the cam cylinder of the machine, all shown in vertical section. Fig. 2 is a detail view of thejoint in the standard of the actuating device. Fig. 3 is a detail view, in vertical section, through one of the segmental pieces which together constitute the hold-down. Figs. 4: to 7, both inclusive, illustrate another form of the device, in which the details are varied,though the underlying principle of operation remains the same; Fig. 4' being a central vertical section through the needle cylinder, cam cylinder and hold-down Fig. 5 being a top or plan view of the holddown; Fig. 6 being a partial horizontal section thereof, and Fig. 7 being a partial vertical section thereof, at right angles to the plane of the section of Fig. 4.

Referring to the type of the device shown in Fig. 1, A represents the cam cylinder of an ordinary circular knitting machine, B the needle cylinder, 0 the needles, with the fabric D, thereon. Upon armsE, suspended from the under side of the bed-plate, or in any other convenient manner,I support a vertical post F, rising centrally into the lower part of the needle cylinder. This post terminates in bifurcated arms G, stayed by a cross-piece G.

The hold-down proper consists of the pieces H, I, approximately segmental in form, and hereinafter referred to as segments, each of which extends throughout a semicircle, and which are both pivoted at J, J, to the top of the arms Gr, so as to be capable of vertical oscillation upon said pivots. I prefer to'mount on the lower side of the segments H, I, a series of teeth Z, adapted to engage in the fabric, but this arrangement is not essential, as in many cases the frictional contact between the segments and the fabric is sufficient. At

the centers of the segments are inwardly projecting arms, K, L, respectively, each of which extends nearly across the circle included by the two segments, but in such a manner as Serial No. 315,150. (No model.)

not to interfere with one another. These arms terminate inwardly in vertical projections Q, B, respectively, rounded on top. Springs S, S, extend from the standard F, to each of the segments H, I, and norm ally tend to pull them downward.

Upon the outside of the rotating cam-cylinder A, I mount upon a hinge N, an overhanging standard M, upon whose downwardly depending inner end is a horizontally journaled roller P. The inward projection of the overhanging standard is such that the roller P, shall, in rotating with the cam-cylinder, strike against the projections Q, R, upon the arms K, L, respectively, and in riding over them depress the inner ends of said arms, thus raising the segments to which they are respectively attached.

Upon the outside of the standard M, I mount, adjacent to the hinge N, a sliding bolt 0, which, when depressed, holds the standard rigidly in a vertical position, but when raised, permits it to be turned outward so as to throw the roller P, clear of the projections Q, R.

The operation of the device is as follows:- As the cam-cylinder A, rotates, the roller P, strikes successively against the projections Q, R, and in passing depresses that end of the arm K, or L, and raises the segment H, or I, as the case may be, out of contact with the fabric, but as soon as the roller P, has passed and thus freed the arm, the segment which has been raised drops, or is pulled down by its spring, and in falling re-engages with the fabric at a higher level than before. As the segment continues to descend, it holds down or pulls slightly upon the work from the inside, thus facilitating the knitting operation. This action of the segmen tal hold-downs takes-place alternately upon opposite sides of the cylinder in the manner stated.

In the modification shown in Figs. 4 to 7, both inclusive, the segmental hold-down, instead of being pivoted, are mounted upon vertically sliding posts whose lower ends are acted upon by levers actuated by the roller mounted upon a rotating standard in a similar manner to that which has just been described. The parts of this device which substantially correspond with those just de scribed, are indicated by small letters corresponding with the large letters before employed; thus, (1 represents the cam-cylinder, b the needle cylinder, and c the needles with the fabric d, thereon. The segmental holddowns h, 'i, are each supported by a pair of posts it, h,t",t", respectively, said posts sliding in vertical guide openings through a central table W, mounted upon the bifurcated arms g, which rise from the top of the central post f. The overhanging standard m, mounted upon the outside of the cam-cylinder, carries at its inner end a horizontally j ournaled roller 19, so arranged as to strike in rotating alternately against the double-inclined heads 13g, of vertically sliding rods U, V, respectively, which rods pass through guide openings in the table The lower end of the rod U, rests upon one arm u, of a lever which is journaled upon a horizontal shaft or pivot 25, extending across between the bifurcations g, g. The other arm u, of said lever is provided with a right angled flat projection M at one side, and at the other side is connected by a downwardly depending U-shaped piece 10 with a flat proj ection M, which extends at right angles from an arm to, pivoted upon the shaft t. The lower end of the rod V, rests upon a lever arm 1;, also pivoted upon the shaft t, and having at its other arm t), a flat projection v connected by a piece '0 with parts c b the exact counterparts of those just described. The lower ends of the sliding posts h, h, which support the segment h, rest upon the flat pro jections c '0 and the posts 71, t, supporting the segment 1', rest upon the flat projections 11?, to, so that when either the lever arm 1;, or the lever arm '11,, is depressed by the rod V, or U, the post resting upon the opposite side will be raised, and in rising will lift the segment which they support. This depression of the rods U, V, is of course efiected by the roller 19, in its passage over the inclined tops, and the rising and falling of the segments occurs alternately, in the manner before described, but with the single exception that instead of the motion being upon a pivot or hinge, it is in a true vertical plane, and thus avoids the difference in the extent of motion at the different points, which necessarily occurs where the segments are pivoted.

The weight of the segments H, I, should be sufficient to cause their descent with the fabric, as soon as their respective elevating levers have been freed from pressure by the actuating mechanism.

I am aware that it is not, broadly speaking, new to combine with a circular knitting machine a segmental hold-down and means for actuating the same, and I therefore do not claim such combination broadly.

Having thus described my invention, I

claim- The combination, with the needle-cylinder and the cam-cylinder; of the vertically movable segments fitting within the needle cylinder; the lever arms each having one end arranged in operative relation to one of said segments and projecting inwardly substantially across the open space between said segment and the opposite segment; and an overhanging standard mounted upon the cam-cylinder and adapted to engage with and depress the inner ends of said levers in passing by the same, substantially as set forth.

HARRY O. RIGHTMIRE. Witnesses:

CHARLES F. ZIEGLER, JAMES H. BELL. 

